Author and Astrophysicist

A Cosmic Picture of Your Ancestors

Big news this week! The full data set from the Planck satellite has finally been released to the public and the scientific community at large. Cosmologists around the world have been itching to see this data for years, and with good reason: Planck has given us our sharpest full-sky image of the cosmic microwave background radiation, the oldest light in the universe. It’s a fantastically detailed set of “baby pictures” of our universe when it was less than 0.003% its current age. Planck has already told us that our universe has a little more dark matter and “regular” matter — stuff made of atoms — than we had previously suspected, and a little less dark energy. Planck also indicates that the universe is a little older than we had thought, to the tune of about 100 million years (so a little less than 1% older). And Planck may not be done changing our understanding of the universe: over the next few years, cosmologists around the world will be trawling through this data set, hunting for something new and strange. Phil Plait has an excellent summary with more details here.

The difference in temperature between the reddest red spot and the bluest blue spot in the Planck image is only about one part in 100,000 — about 0.0003 degrees Celsius. But the thing that always gives me the chills — in a good way — about this kind of image is the fact that these tiny differences are what led, very directly, to you and me. Those little temperature differences were caused by tiny clumps of matter in the universe 13.8 billion years ago. And over all that time between then and now, those tiny clumps got huge — the clumps attracted other clumps through gravity — and became the galaxies and stars and planets we see in the universe today. So everything you see around you, everything you know and love, everything from the stars in the sky to the fish in the ocean to the computer you’re reading this on, all of it is directly descended from those tiny temperature differences in the image from Planck. In other words: that’s a picture of you, and me, and everyone and everything else, 13.8 billion years ago.

There’s also news of another sort: for the next six months, I’ll be working at New Scientist’s San Francisco office, creating interactive online graphics and reporting on news in astronomy, physics, and other areas of science. My first set of graphics — about Planck, naturally — went live on the New Scientist site today! I’m really excited to be working at NS, and I hope to have more of my work with them to post here soon.